512 On a Visit to Babel Island. 



visited tlie island and liberated them on Monday afternoon, 

 November 25. 



The member who liberated them stated that no eggs had 

 been deposited in the barrel. There is no doubt whatever 

 that these four birds would have deposited their eggs during 

 the evening of the 23rd if they had not been placed in cap- 

 tivity. I think there is sutficient evidence to show that if 

 unfavourable conditions are brought about this bird has 

 the power to withhold the depositing of an egg upon or 

 about a certain date. 



Whether the four birds confined had the physical power 

 of controlling those functions responsible for the expulsion 

 of the egg from the oviduct, or such functions became semi- 

 paralysed for the time through fear combined with being" 

 confined in an unsuicable place, is knovvn only to the 

 captives themselves. 



No doubt after incubation starts the male returns each 

 night to the burrow and feeds the female bird, and she 

 leaves the burrow for exercising purposes, the male taking 

 her place upon the egg in her absence. I have dissected in 

 iny time about 100 birds, taken from the burrows during 

 the daytime, all birds being females — i. e. after incubation 

 started. 



Indications point to the fact that after the egg is deposited 

 the male bird takes the place of the female in the burrow 

 during the day following, purely to protect the egg before 

 the female bird starts to sit in earnest to incubate the egg. 



This practice is common with many male birds of the 

 same nesting habits, particularly those that deposit more 

 than the one egg. The male bird simply stands over the egg 

 in the nest until the last egg has been deposited. When the 

 female starts incubation in earnest, in some cases the male 

 protects the nest and egg by remaining close by and attacking 

 any intruders. With Cuckoos they simply take possession of 

 the nest until the egg is deposited or placed therein. After 

 careful observations for years I have noticed this. The 

 male bird takes his share of incubation in many instances, 

 but not to generate heat, simply to retain the same while 

 the female is awav from the nest fcedinir or exercising. 



